The present invention relates to a fill metering system for powdery or granular fill material of the type composed of metering devices connected ahead of shut-off, or flow blocking means and in which containers to be filled are automatically and successively brought underneath the shut-off means and receive a measured quantity of the fill material during the time the shut-off means are open.
Known devices of this type have the drawback that during the filling of a container, the air displaced out of the container by the fill material carries along a rather large quantity of the fill material so that, in spite of the provision of an extraction hood, the fill station will very soon be completely enveloped in dust and must be cleaned rather frequently.
Detailed studies have shown that this is mainly the result of the fact that during filling of a container, the fill material flows vertically downwardly while the air in the container whirls away toward all sides. This air turbulence is, generally, even augmented by the fact that the shut-off means are usually constituted by two pushers which are guided in opposite directions and which open and close above the container in a scissors-like manner. The operating rhythm of such a device cannot, in practice, be increased to more than 100 fills per minute because at higher rates the air turbulence would prevent accurate filling of the containers.